Method of forming a milk sampling tube



Feb. 18, 1958 2,824,032

METHOD OF FORMING A MILK SAMPLING TUBE E. L. RACKLEFF Filed July 27, 1954 //\/A/E./\/TUF EL 5 RACKLE'FF ATTUFA/Ev United States Patent METHOD OF FORMING A MILK SAMPLING TUBE Ellis L. Rackletl, Eugene, Oreg.

Application July 27, 1954, Serial No. 446,067

3 Claims. (Cl. 154-83) This invention relates generally to the dairy industry .and particularly to a single service milk sampling tube and a method of forming same.

It is well understood in the industry that sampling tubes of glass or metal have long been in use. These are commonly twenty-four inches long and five-sixteenths of an inch inside diameter. This type of tube is objectionable on account of its first cost, loss by pitting on metal parts, and by breaking of glass parts, and the cost of cleaning, sterilization, and wrapping and transportation between point of sampling and points of sterilization. Such tubes are never free from doubt as to proper sterilization.

It is to overcome these objections that my tube has been devised.

The main object of my invention is the production of an expendable sampling tube which will be economical in use and will remove all doubt as to the sanitation since it is only used once.

I accomplish these and other objects in the manner set forth in the following specification as illustrated in the accompanying drawing, in which:

Fig. 1 is a longitudinal section through the sampling tube.

Fig. 2 is a section taken along the line 2-2 in Fig. 1, showing the plastic tube a tight fit in paper tube, due to expansion during sterilizing.

Fig. 3 is similar to Fig. 2 but showing the plastic tube a loose fit in paper tube before sterilizing.

Fig. 4 is an elevation showing use and one way of closing one end to prevent loss of liquid contained in the sampling tube.

Fig. 5 is a perspective view of the tube container, showing one tube partially removed.

Fig. 6 is an elevation of the container partly in section.

Fig. 7 is a view taken along the line 77 in Fig. 6.

Fig. 8 is similar to Fig. 7 but showing the closure cover moved so as to close the container.

Referring in detail to the drawing, there is shown a paper straw, or tube 10, approximately twenty-four inches long, into one end of which is inserted a reinforcing lining 11 of a plastic tubing known to the trade as polystyrene, a characteristic of which is a marked expansion in dimension at sterilizing temperatures, which expansion causes the liner 11 to fit tightly into the straw 10 and form a sealed support for the end of the tube which is held in the hand when milk is being sampled. Upon cooling to room temperature the plastic lining 11 does not return to its original size but retains suflicient enlargement to grip the inside of tube 10 for efiective retention therein.

The sterilizing temperature is preferably produced according to conventional practice and the requirements of the industry by the application of saturated steam between about 121.2 C. and about 126 0., although any temperature above 100 C. which will not damage the paper tube may be used.

In Fig. 4 is shown a milk container 12 into which the tester is inserted with the reinforced end 13 uppermost.

When the liquid, milk, or cream 14 has risen within the tube 10, the end 13 is closed by placing a finger across the top end 13 until the sample can be properly transferred to the desired container.

In Figs. 6, 7 and 8 are shown the containers 17, which may be of any desired material, such as a heavy parafiin treated tube which will resist predetermined amounts of dampness, heat and pressure and approved sterilization. The container 17 has a sealed bottom 18, which acts as a closure for the filling end of the container and is sealed after the container is filled with sampling tubes.

The top edge of the container 17 has an outturned flange 20 within which is placed a lower disk 21 having a hole 22 formed near its outer edge. Above the disk 21 is placed a cap 23, having a hole 24 which can be brought into register with the hole 22 when the cap 23 is rotated. In this position and with the container tilted at about 45 from the horizontal, a tube 10 may be ejected from the holes 22 and 24.

It can be seen from the foregoing that there is provided an expendable tube which will be simple to operate and inexpensive to use, as well as positive in its sanitary functioning.

The cap 23 has formed around the circumference thereof a flange 25, whose lower edge 26 is inturned beneath the flange 20.

I claim:

1. A method of making sampling tubes comprised of progressively forming a paper straw the total length of the desired tube, then forming a tubular liner of plastic material having the property of acquiring a substantial permanent expansion when heated, such as polystyrene, then placing said liner Within one end of said straw, and then applying sterilizing heat to said straw and liner in the approximate range between C. and 126 C.

2. A method of forming expandable sampling tubes comprised of forming a flexible straw of paper, then forming a tubular liner of polystyrene, then slipping said liner into one end of said straw and then subjecting said straw and liner to a sterilizing temperature in the approximate range of 121 C. to 126 C.

3. The method of making and sterilizing a sampling tube comprising forming a paper tube, forming a tubular liner of a plastic material having the property of acquiring a substantial permanent expansion when heated, such as polystyrene, said liner being formed to an outside diameter slightly smaller than the inside diameter of said tube, inserting said liner loosely in said tube, and then subjecting said tube and liner to a sterilizing temperature between 100 C. and approximately 126 C. to expand said liner permanently into binding engagement with said tube and thereby indicate that the tube and liner have been sterilized.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Plastics Technology, Stretch Orientation of Polystyrene and Its Interesting Results, India Rubber World, May 1948, pp. 225-231. 

1. A METHOD OF MAKING SAMPLING TUBES COMPRISED OF PROGRESSIVELY FORMING A PAPER STRAW THE TOTAL LENGTH OF THE DESIRED TUBE, THEN FORMING A TUBULAR LINER OF PLASTIC MATERIAL HAVING THE PROPERTY OF ACQUIRING A SUBSTANTIAL PERMANENT EXPANSION WHEN HEATED, SUCH AS POLYSTRENE, THEN PLACING SAID LINER WITHIN ONE END OF SAID STRAW, AND THEN APPLYING STERILIZING HEAT TO SAID STRAW AND LINER IN THE APPROXIMATE RANGE BETWEEN 100*C. AND 126*C. 